Using Agronomy for Post-Harvest Fertilizing Decisions

The importance of post-harvest fertilization in permanent crops cannot be overstated. That’s because with permanent crops, we are always “farming for next year’s crop.” Even in season, any amount of fertilizer we under apply will affect the following year’s crop. Therefore, we must be diligent each fall to ensure the crop will have adequate nutrients when it starts to grow again in the spring.

Given the importance of this application timing, we need to determine several factors before we can decide the type and amount of nutrients to apply. How much of each nutrient was taken off by the last crop, and what is your yield goal for next year? We have several tools at our disposal to help us answer these questions. Take PlantCalc, for example. This app allows the user to choose a crop and yield goal for next year. Then, it will calculate a removal rate of N, P and K that will be required to achieve that yield goal. This calculator can be also be used to determine the amount of nutrients removed by last year’s crop. All you have to do is enter last year’s yield, and it will give you the nutrient removal rate for that yield.

PlantCalc is one way to quickly determine removal and nutrient requirements, but a soil and tissue analysis is the best, most accurate way to determine actual nutrient levels in the soil and in the plant. It is best to take regular samples during the season so you don’t find yourself playing catch-up.  The soil and tissue analysis gives a much more in-depth look at the soil biology and nutrient bank the plant has to draw from. The results from these samples and the calculations from the PlantCalc app will give you valuable information to help determine not only the type of fertilizer, but also the amount. This in turn will give you piece of mind that you made the best decision for your crop and are probably not over or under-applying your nutrients. That also means you are spending your hard-earned dollars wisely.

Helena has well-trained and experienced field personnel ready to help you get the most out of your investments. We have an excellent agronomy staff with many years of experience in analyzing water, soil and tissue samples. They can help you make the best agronomic decisions to maximize yields, using detailed programs based on science. Don’t make an uneducated guess when deciding on your fall fertilizer program. Ask your Helena field representative about implementing Helena agronomy and AGRIntelligence services on your farm.

- Greg Selna, Product Manager